package com.example.myapplication.knowledges

//fun main() {
//    println("hhhhhh哈哈哈哈")
//    println('f')
//    println()
//    println("123")
//    println(123)
//    println(45)
//
//    //帮我写一个常量
//    val a = 1
//    //帮我写一个变量
//    var b = 1
//}

fun main() {
    val num1 = 10
    // num1 = 30   //报错 Val cannot be reassigned
    var num2 = 20
    num2 = 40
    println("num2 = $num2")

    val companyName: String = "itCast"
    println("companyName:$companyName")
}